Hydrocyanation reaction method

Abstract

The invention provides a hydrocyanation reaction method, the hydrocyanation reaction method is carried out in a reaction system containing aromatic amine under the action of a nickel-bidentate phosphite ligand catalyst, the structure of the aromatic amine is # imgabs0 #, and X1-X3 groups and Y1-Y3 groups respectively comprise any one of hydrogen, alkyl, alkoxy, alkylamino, hydroxyl and amino. The hydrocyanation reaction method is high in reaction efficiency, accumulation of ligand hydrolysate can be remarkably reduced or eliminated, and the effective content of a catalyst in a reactant is stabilized; in addition, the hydrocyanation reaction method has the advantages of high reaction efficiency, few side reactions, high raw material conversion rate and high product selectivity, and can meet the requirements of a large-scale production process for preparing adiponitrile by using a butadiene direct hydrocyanation method.

Description

Technical Field

[0001] The invention relates to the technical field of chemical synthesis, and in particular to a hydrocyanation reaction method. Background Art

[0002] Adiponitrile (ADN) is an important raw material intermediate for the production of nylon 66 and an important link in the nylon and specialty polyurethane industry chain. Among the various methods for producing adiponitrile, the direct hydrocyanation of butadiene is the mainstream process and has the highest global production capacity.

[0003] The process route for preparing adiponitrile by direct hydrocyanation of butadiene is as follows:

[0004]

[0005] The specific reaction steps include: a one-step hydrocyanation reaction, in which butadiene is reacted with hydrocyanic acid (HCN) under the action of a nickel catalyst to generate 2-methyl-3-butenenitrile (2M3BN) and 3-pentenenitrile (3PN); a 2M3BN isomerization reaction, in which 2M3BN is isomerized to 3PN under the action of a nickel catalyst; a two-step hydrocyanation reaction, in which 3PN is isomerized to 4-pentenenitrile (4PN), and then reacted with HCN to generate ADN and a by-product 2-methylglutaronitrile (MGN). This step of the reaction requires a nickel catalyst and a Lewis acid additive, has high requirements on the catalyst activity, and is a key step in the entire reaction.

[0006] The direct hydrocyanation of butadiene involves a two-step hydrocyanation process. Taking the one-step hydrocyanation reaction as an example, the specific hydrocyanation reaction process is as follows:

[0007]

[0008] Among them, the zero-valent nickel-phosphorus catalyst [NiL4] (L is a ligand) removes a ligand molecule to form [NiL3], which then combines with HCN to form [HNiL3CN]; it continues to lose a ligand molecule to form [HNiL2CN], and then combines with butadiene to form an intermediate [C4H6-HNiL2CN]. This intermediate can react along two paths to generate two different substances, 3PN and 2M3BN, and regenerate [NiL3] to continue to participate in the catalytic cycle reaction.

[0009] However, in actual production, there are many difficulties. First, the presence of water in the reaction system may cause the phosphite ligand of the nickel catalyst to hydrolyze, produce acidic hydrolysis products, further accelerate the ligand hydrolysis, and gradually cause the nickel-bidentate phosphite ligand catalyst to deactivate; second, when the HCN concentration in the reaction system is high, it will attack the active nickel ([NiL3] and [NiL2], etc.) of the hydrocyanation reaction, generate nickel cyanide (Ni(CN)2) precipitate, and cause the catalyst to deactivate; third, the hydrocyanation reaction (especially the two-step hydrocyanation reaction) has a slow rate and a long residence time, resulting in a high amount of catalyst deactivation. In addition, the occurrence of side reactions in the hydrocyanation reaction (such as a large amount of 2-methylglutaronitrile as a byproduct of the two-step hydrocyanation reaction) limits downstream applications, which not only reduces the reaction efficiency, but also increases production costs.

[0010] Therefore, developing a hydrocyanation reaction process with high reaction efficiency, high catalyst stability and high product selectivity is a technical problem that needs to be solved urgently. Summary of the invention

[0011] In view of the deficiencies in the prior art, the present invention discloses a hydrocyanation reaction, which comprises a specific nickel-bidentate phosphite ligand catalyst and an aromatic amine for catalyzing the hydrocyanation reaction, thereby improving the raw material conversion rate and product selectivity, reducing the occurrence of side reactions, and significantly reducing the catalyst consumption, thereby improving the stability of the overall process.

[0012] In order to achieve the above technical objectives, on the one hand, the present invention provides a hydrocyanation reaction, wherein the hydrocyanation reaction is carried out in a reaction system containing an aromatic amine under the action of a nickel-bidentate phosphite ligand catalyst, wherein the structure of the aromatic amine is:

[0013]

[0014] Among them, X 1 -X 3 Group and Y 1 -Y 3 The groups include any one of hydrogen, alkyl, alkoxy, alkylamino, hydroxyl, and amino.

[0015] The above technical solution uses nickel-bidentate phosphite ligand as a catalyst. In the hydrocyanation reaction, the bidentate phosphite ligand has a weaker complexation with metal nickel than the traditional monodentate phosphite ligand, and is easy to be freed to produce active nickel intermediates to promote the occurrence of the hydrocyanation reaction; but at the same time, the active nickel intermediates (such as [NiL3] and [NiL2], etc.) are in a naked state due to the partial loss of the ligand, and are easily attacked by polar molecules such as hydrocyanic acid and water, thereby generating nickel cyanide and hydrolysis products, causing catalyst loss. The aromatic amine used in the above technical solution has a strong complexation with metal nickel, which can be coordinated with the active nickel intermediate in time during the reaction, thereby protecting the active nickel intermediate and reducing catalyst loss.

[0016] Therefore, the hydrocyanation reaction of the present invention can reduce catalyst loss and by-product generation during the hydrocyanation reaction through the synergistic optimization of the nickel-bidentate phosphite ligand catalyst and the aromatic amine, and efficiently catalyze the hydrocyanation reaction.

[0017] In a further example of the present invention, 1 -X 3 Group and Y 1 -Y 3 The structure of the group is optimized. Optionally, the structural formula of the alkyl group is -R, and the structural formula of the alkoxy group is The structural formula of the alkylamino group is Wherein, the R group includes any one of methyl, ethyl, isopropyl and tert-butyl.

[0018] In some optional examples of the present invention, the aromatic amine can be selected from any one of Table 1.

[0019] Table 1

[0020]

[0021]

[0022] In a further example of the present invention, the structure of the ligand used in the nickel-bidentate phosphite ligand catalyst is optimized. Optionally, the structure of the ligand used in the nickel-bidentate phosphite ligand catalyst is:

[0023]

[0024] Among them, R 1 -R 4 and Z 1 -Z 5 The groups include any one of hydrogen, methyl, ethyl, isopropyl, tert-butyl, and methoxy. In the specific process, those skilled in the art can select a suitable bidentate phosphite ligand according to needs.

[0025] In a further example of the present invention, the ratio of the nickel-bidentate phosphite ligand catalyst to the aromatic amine in the hydrocyanation reaction is explored and optimized. Optionally, the mass ratio of the nickel-bidentate phosphite ligand catalyst to the aromatic amine is 1:(0.05-0.8), and further 1:(0.1-0.6) is optional, which is conducive to the effective coordination of the aromatic amine and the active nickel intermediate during the hydrocyanation reaction and improves the stability of the catalyst.

[0026] In a further example of the present invention, the ratio of the nickel-bidentate phosphite ligand catalyst to the aromatic amine in the hydrocyanation reaction is explored and optimized. Optionally, the mass ratio of the nickel-bidentate phosphite ligand catalyst to the aromatic amine is 1:(0.05-0.8), and further 1:(0.1-0.6) is optional, which is conducive to the effective coordination of the aromatic amine and the active nickel intermediate during the hydrocyanation reaction and improves the stability of the catalyst.

[0027] In a further example of the present invention, the hydrocyanation reaction method is a hydrocyanation reaction method for preparing adiponitrile.

[0028] Furthermore, the hydrocyanation reaction method includes a one-step hydrocyanation reaction method for preparing pentenenitrile using butadiene as a raw material.

[0029] Furthermore, the reaction temperature of the one-step hydrocyanation reaction method is 40-110°C, preferably 50-95°C. This temperature range is relatively mild, easy to control, and has strong process operability.

[0030] It should be noted that the pressure of the one-step hydrocyanation reaction method in the present invention is not limited and can be selected to be 1-5 bar.

[0031] Furthermore, the reaction time of the one-step hydrocyanation reaction method is 1-5 hours. Through the analysis of the embodiments and comparative examples, it can be seen that the technical solution of the present invention can significantly increase the reaction rate, shorten the reaction time, and improve the overall process production efficiency.

[0032] Furthermore, when the hydrocyanation reaction method is a one-step hydrocyanation reaction method, X in the structure of the aromatic amine 1 , X 3 , Y 1 , Y 3 The groups are selected from hydrogen or alkyl, X 2 , Y 2 The groups are each selected from alkyl or alkoxy groups.

[0033] Furthermore, in the one-step hydrocyanation reaction method, the mass ratio of the nickel-bidentate phosphite ligand catalyst to butadiene is (0.5-3):1000, preferably (0.75-2.5):1000. The present invention can significantly improve the stability of the catalyst during the one-step hydrocyanation reaction method and increase the reaction rate by adding a trace amount of a specific aromatic amine substance; after the reaction is completed, the aromatic amine can be separated through a separation and purification process, such as extraction, distillation or extractive distillation, and a high-purity pentenenitrile product can be obtained.

[0034] Furthermore, the hydrocyanation reaction method also includes a two-step hydrocyanation reaction method for preparing adiponitrile using pentenenitrile as a raw material.

[0035] Furthermore, the reaction temperature of the two-step hydrocyanation reaction method is 35-90°C, preferably 40-80°C. This temperature range is relatively mild and easy to control, and the overall process has strong operability.

[0036] It should be noted that the pressure of the two-step hydrocyanation reaction method in the present invention is not limited and can be selected to be 1-5 bar.

[0037] Furthermore, the reaction time of the one-step hydrocyanation reaction method is 1-10 hours. Through the analysis of the embodiments and comparative examples, it can be seen that the technical solution of the present invention can significantly increase the reaction rate, shorten the reaction time, and improve the overall process production efficiency.

[0038] Furthermore, in the two-step hydrocyanation reaction method, X in the structure of the aromatic amine 1 , X 3 , Y 1 , Y 3 The groups are selected from any one of hydrogen, alkyl or alkoxy, X 2 , Y 2 The groups are selected from alkoxy or alkylamino groups.

[0039] Furthermore, in the two-step hydrocyanation reaction method, the mass ratio of the nickel-bidentate phosphite ligand catalyst to pentenenitrile is (0.5-3):1000, preferably (0.75-2.5):1000. The present invention can significantly improve the stability of the catalyst during the one-step hydrocyanation reaction method and increase the reaction rate by adding a trace amount of a specific aromatic amine substance; after the reaction is completed, the aromatic amine can be separated through a separation and purification process, such as extraction, distillation or extractive distillation, and a high-purity adiponitrile product can be obtained. .

[0040] Furthermore, the two-step hydrocyanation reaction method is carried out with the participation of a co-catalyst, and the addition of the co-catalyst is beneficial to synergistically improving the stability and reaction rate of the catalyst; the co-catalyst includes one of zinc chloride, aluminum chloride, ferric chloride, titanium tetrachloride, and triphenylboron.

[0041] Furthermore, the mass ratio of the nickel-bidentate phosphite ligand catalyst to the co-catalyst is (0.2-0.8):1, preferably (0.3-0.7):1. By optimizing the dosage of the catalyst and the co-catalyst, the reaction rate can be synergistically optimized with the aromatic amine to reduce the occurrence of side reactions and improve the reaction efficiency.

[0042] Compared with the prior art, the present invention has the following beneficial effects: the hydrocyanation reaction method of the present invention includes a nickel-bidentate phosphite ligand catalyst and an aromatic amine with a specific structure, which can not only reduce the reaction time of the catalyzed hydrocyanation reaction method, but also significantly reduce or eliminate the accumulation of ligand hydrolysis products, and stabilize the effective content of the catalyst in the reaction body; in addition, the hydrocyanation reaction method of the present invention has high reaction efficiency, few side reactions, high raw material conversion rate and product selectivity, and can meet the needs of a large-scale production process of direct hydrocyanation of butadiene to produce adiponitrile. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] The drawings constituting a part of the present application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0044] Figure 1 The gas chromatogram of Example 5 of the present invention after reaction for 2 hours is shown. DETAILED DESCRIPTION

[0045] In order to facilitate the understanding of the present invention, the present invention will be described more comprehensively below, and preferred embodiments of the present invention are given. However, it should be understood that these embodiments are only used for more detailed description and should not be understood as limiting the present invention in any form, i.e., not intended to limit the scope of protection of the present invention.

[0046] Unless otherwise defined, the technical terms used in the following examples have the same meanings as those generally understood by those skilled in the art to which the present invention belongs. The test reagents used in the following examples, unless otherwise specified, are all conventional biochemical reagents; the experimental methods, unless otherwise specified, are all conventional methods.

[0047] It should be noted that in the nickel-bidentate phosphite ligand catalyst described in the present invention, the coordination number of nickel and the bidentate phosphite ligand is generally 2 or 3, generally 2; the present invention aims to solve the technical problem of catalyst instability during the hydrocyanation reaction method in the prior art, so the embodiment of this application will no longer describe the ratio of the number of each nickel and the bidentate phosphite ligand.

[0048] Regarding the conversion rate of the hydrocyanation reaction method, the gas chromatography peak area percentage is used for calculation, wherein the conversion rate of the one-step hydrocyanation reaction method = (2M3BN + 3PN) / (2M3BN + 3PN + butadiene) × 100%, 3PN selectivity = 3PN / (2M3BN + 3PN) × 100%; the conversion rate of the two-step hydrocyanation reaction method = (ADN + MGN) / (ADN + MGN + 3PN) × 100%, ADN selectivity = ADN / (ADN + MGN) × 100%.

[0049] The content of the catalyst in the reaction system of the embodiment of the present invention can be characterized by the Ni content in the clear liquid.

[0050] Example 1

[0051] A one-step hydrocyanation reaction method, wherein butadiene is used as a raw material to prepare pentenenitriles in a reaction system containing aromatic amines under the catalysis of a nickel-bidentate phosphite ligand catalyst, specifically:

[0052] (1) Material preparation: The catalyst used in this embodiment is a nickel-bidentate phosphite ligand catalyst, wherein the bidentate phosphite ligand L21 has the structural formula:

[0053]

[0054] It has the substituent structure shown in Table 2:

[0055] Table 2

[0056] Ligand L21 <![CDATA[R 1 ]]> <![CDATA[R 2 ]]> <![CDATA[R 3 ]]> <![CDATA[R 4 ]]> <![CDATA[Z 1 ]]> <![CDATA[Z 2 ]]> <![CDATA[Z 3 ]]> <![CDATA[Z 4 ]]> <![CDATA[Z 5 ]]> Substituents Isopropyl hydrogen methyl hydrogen methyl hydrogen Tert-butyl hydrogen methyl

[0057] The ligand L21 and nickel powder are combined to prepare a nickel-bidentate phosphite ligand catalyst.

[0058] It should be noted that the nickel powder mentioned in the embodiments of the invention is nickel powder that can be purchased commercially. In addition, the preparation process of the ligand and the preparation process of the nickel-bidentate phosphite ligand catalyst in the embodiments of the present invention are only preferred demonstrations. Those skilled in the art can prepare the ligand or the nickel-bidentate phosphite ligand catalyst by other methods through non-creative labor, and under certain working conditions, the appropriate type of ligand or nickel-bidentate phosphite ligand catalyst can be directly purchased based on the technical solution of the present invention, and the protection scope of the present invention is not limited thereby.

[0059] (2) One-step hydrocyanation reaction method: nickel-bidentate phosphite ligand catalyst (2 mmol), aromatic amine A2 (1.0 mmol) and butadiene (2.0 mol) were placed in a stainless steel reactor. After replacing with nitrogen, the reaction system was heated to 50°C. Then, hydrocyanic acid (1.9 mol) was slowly added to the reactor using a pump for 2 hours. After the addition was completed, the reaction was continued at 50°C. As the reaction proceeded, samples were taken from the reaction system at different times for analysis. The results are shown in Table 3.

[0060] Table 3

[0061] Reaction time / h Butadiene / wt% 3PN / wt% 2M3BN / wt% Clear liquid Ni / ppm Conversion rate / % 3PN selectivity / % 1 32.35 61.16 6.49 353 67.65 90.41 2 22.52 69.13 8.35 339 77.48 89.22 3 17.16 74.61 8.23 337 82.84 90.07 4 10.15 80.72 9.13 331 89.85 89.84 5 3.23 86.54 10.23 329 96.77 89.43

[0062] Table 3 shows that in the one-step hydrocyanation involving the bidentate nickel-bidentate phosphite ligand catalyst and aromatic amine A2, the selectivity of 3PN reaches about 90% with few side reactions; and the Ni content of the clear liquid does not change much during the reaction, indicating that the performance of the catalyst is relatively stable during the reaction.

[0063] Example 2

[0064] A one-step hydrocyanation reaction method, which uses butadiene as a raw material to prepare pentenenitriles in a reaction system containing aromatic amines under the action of a nickel-bidentate phosphite ligand catalyst, specifically:

[0065] (1) Material preparation: The catalyst used in this example is a nickel-bidentate phosphite ligand catalyst, wherein the bidentate phosphite ligand L22 has the same structural formula as that of the ligand L21, but the ligand L22 has a substituent structure shown in Table 4:

[0066] Table 4

[0067] Ligand L22 <![CDATA[R 1 ]]> <![CDATA[R 2 ]]> <![CDATA[R 3 ]]> <![CDATA[R 4 ]]> <![CDATA[Z 1 ]]> <![CDATA[Z 2 ]]> <![CDATA[Z 3 ]]> <![CDATA[Z 4 ]]> <![CDATA[Z 5 ]]> Substituents Isopropyl methyl methyl hydrogen methyl Ethyl Tert-butyl hydrogen methyl

[0068] The ligand L22 and nickel powder are combined to prepare a nickel-bidentate phosphite ligand catalyst.

[0069] (2) One-step hydrocyanation reaction method: The nickel-bidentate phosphite ligand catalyst (5 mmol), aromatic amine A4 (0.5 mmol) and butadiene (2.0 mol) were placed in a stainless steel reactor, replaced with nitrogen, and the reaction system was heated to 95°C; then hydrocyanic acid (1.9 mol) was slowly added to the reactor using a pump, and the addition time lasted for 2 hours; after the addition was completed, the reaction was continued at 95°C; as the reaction proceeded, the reaction system was sampled and analyzed at different times, and the results are shown in Table 5.

[0070] Table 5

[0071] Reaction time / h Butadiene / wt% 3PN / wt% 2M3BN / wt% Clear liquid Ni / ppm Conversion rate / % 3PN selectivity / % 1 31.25 62.23 6.52 345 68.75 90.52 2 21.52 70.14 8.34 339 78.48 89.37 3 16.21 76.15 7.64 340 83.79 90.88 4 9.25 81.72 9.03 342 90.75 90.05 5 3.25 86.45 10.3 339 96.75 89.35

[0072] It can be verified from Table 5 that the one-step hydrocyanation reaction method catalyzed by the catalyst combination of the present invention has high raw material conversion rate and product selectivity, few side reactions, high catalyst retention rate and stable catalytic performance.

[0073] Example 3

[0074] A one-step hydrocyanation reaction method, which uses butadiene as a raw material to prepare pentenenitriles in a reaction system containing aromatic amines under the action of a nickel-bidentate phosphite ligand catalyst, specifically:

[0075] (1) Material preparation: The catalyst used in this example is a nickel-bidentate phosphite ligand catalyst, wherein the structural formula of the bidentate phosphite ligand L23 is the same as that of the ligand L21, but the ligand L23 has a substituent structure shown in Table 6:

[0076] Table 6

[0077] Ligand L23 <![CDATA[R 1 ]]> <![CDATA[R 2 ]]> <![CDATA[R 3 ]]> <![CDATA[R 4 ]]> <![CDATA[Z 1 ]]> <![CDATA[Z 2 ]]> <![CDATA[Z 3 ]]> <![CDATA[Z 4 ]]> <![CDATA[Z 5 ]]> Substituents methyl Isopropyl Tert-butyl Methoxy methyl methyl hydrogen methyl Isopropyl

[0078] The ligand L23 and nickel powder are combined to prepare a nickel-bidentate phosphite ligand catalyst.

[0079] (2) One-step hydrocyanation reaction method: nickel-bidentate phosphite ligand catalyst (7.5 mmol), aromatic amine A5 (3.0 mmol) and butadiene (5.0 mol) were placed in a stainless steel reactor. After replacing with nitrogen, the reaction system was heated to 75°C. Then, hydrocyanic acid (1.9 mol) was slowly added to the reactor using a pump for 2 h. After the addition was completed, the reaction was continued at 75°C. As the reaction proceeded, samples were taken from the reaction system at different times for analysis. The results are shown in Table 7.

[0080] Table 7

[0081] Reaction time / h Butadiene / wt% 3PN / wt% 2M3BN / wt% Clear liquid Ni / ppm Conversion rate / % 3PN selectivity / % 1 32.75 60.75 6.5 338 67.25 90.33 2 22.12 70.13 7.75 329 77.88 90.05 3 16.23 75.75 8.02 326 83.77 90.43 4 9.01 81.95 9.04 335 90.99 90.06 5 4.05 86.65 9.3 340 95.95 90.31

[0082] It can be confirmed from Table 7 that under the action of the combination of the nickel-bidentate phosphite ligand catalyst and the aromatic amine A5 catalyst of the present invention, the selectivity of 3PN in the one-step hydrocyanation reaction method is about 90%, and the Ni content of the clear liquid does not change much over time during the reaction, indicating that the catalyst is relatively stable during the reaction.

[0083] Example 4

[0084] A one-step hydrocyanation reaction method, in which the catalyst, reaction raw materials and control parameters used are the same as those in Example 1, except that the aromatic amine added in this example is aromatic amine A11; as the reaction proceeds, the reaction system is sampled and analyzed at different times, and the results are shown in Table 8.

[0085] Table 8

[0086] Reaction time / h Butadiene / wt% 3PN / wt% 2M3BN / wt% Clear liquid Ni / ppm Conversion rate / % 3PN selectivity / % 1 39.25 54.77 5.98 343 60.75 90.16 2 30.31 63.05 6.64 332 69.69 90.47 3 23.22 69.17 7.61 319 76.78 90.09 4 14.75 76.58 8.67 303 85.25 89.83 5 8.35 82.54 9.11 287 91.65 90.06

[0087] Combining Table 3 and Table 8, the effect of the one-step hydrocyanation reaction method containing aromatic amine A2 is relatively better than the effect of the one-step hydrocyanation reaction method containing aromatic amine A11. In the actual reaction process, suitable aromatic amines can be selected according to specific working conditions to catalyze the one-step hydrocyanation reaction method.

[0088] Example 5

[0089] A two-step hydrocyanation reaction method, in which pentenenitrile is used as a raw material to prepare adiponitrile in a reaction system containing aromatic amines under the action of a nickel-bidentate phosphite ligand catalyst, specifically:

[0090] (1) Material preparation: The catalyst used in this example is a nickel-bidentate phosphite ligand catalyst, wherein the bidentate phosphite ligand L24 has the same structural formula as that of the ligand L21, but the ligand L24 has a substituent structure shown in Table 9:

[0091] Table 9

[0092]

[0093]

[0094] The ligand L24 and nickel powder are combined to prepare a nickel-bidentate phosphite ligand catalyst.

[0095] (2) Two-step hydrocyanation reaction method: nickel-bidentate phosphite ligand catalyst (2 mmol), anhydrous zinc chloride (3 mmol), aromatic amine A11 (0.25 mmol) and 3PN (0.8 mol) were placed in a stainless steel reactor. After replacing with nitrogen, the reaction system was heated to 80°C. Then, hydrocyanic acid (0.76 mol) was slowly added to the reactor using a pump, and the addition time lasted for 2 hours. After the addition was completed, the reaction was continued at 80°C. As the reaction proceeded, the reaction system was sampled and analyzed at different times. The results are shown in Table 10. Figure 1 The gas chromatogram of this example at 2 h is shown.

[0096] Table 10

[0097] Reaction time / h 3PN / wt% ADN / wt% MGN / wt% Clear liquid Ni / ppm Conversion rate / % ADN selectivity / % 2 63.9 34.68 1.42 340 36.10 96.07 4 42.9 54.89 2.21 335 57.10 96.13 6 26.7 70.77 2.53 332 73.30 96.55 8 10.5 86.01 3.49 329 89.50 96.10 10 2.3 93.95 3.75 326 97.70 96.16

[0098] It can be verified from Table 10 that in the two-step hydrocyanation involving the nickel-bidentate phosphite ligand catalyst and the aromatic amine A11 of the present invention, the selectivity of ADN reaches more than 96%, the side reactions are relatively few, and the Ni content of the clear liquid does not change much during the overall reaction process, indicating that the catalyst performance is relatively stable.

[0099] Example 6

[0100] A two-step hydrocyanation reaction method, in which pentenenitrile is used as a raw material to prepare adiponitrile in a reaction system containing aromatic amines under the action of a nickel-bidentate phosphite ligand catalyst, specifically:

[0101] (1) Material preparation: The catalyst used in this example is a nickel-bidentate phosphite ligand catalyst, wherein the bidentate phosphite ligand L25 has the same structural formula as that of the ligand L21, but the ligand L25 has a substituent structure shown in Table 11:

[0102] Table 11

[0103] Ligand L25 <![CDATA[R 1 ]]> <![CDATA[R 2 ]]> <![CDATA[R 3 ]]> <![CDATA[R 4 ]]> <![CDATA[Z 1 ]]> <![CDATA[Z 2 ]]> <![CDATA[Z 3 ]]> <![CDATA[Z 4 ]]> <![CDATA[Z 5 ]]> Substituents Tert-butyl hydrogen methyl Methoxy Isopropyl hydrogen Methoxy Ethyl methyl

[0104] The ligand L25 and nickel powder are combined to prepare a nickel-bidentate phosphite ligand catalyst.

[0105] (2) Two-step hydrocyanation reaction method: Nickel-bidentate phosphite ligand catalyst (0.75 mmol), anhydrous titanium tetrachloride (2.5 mmol), aromatic amine A12 (0.45 mmol) and 3PN (1.0 mol) were placed in a stainless steel reactor. After replacing with nitrogen, the reaction system was heated to 40°C. Then, hydrocyanic acid (0.95 mol) was slowly added to the reactor using a pump, and the addition time lasted for 2 hours. After the addition was completed, the reaction was continued at 40°C. As the reaction proceeded, the reaction system was sampled and analyzed at different times. The results are shown in Table 12.

[0106] Table 12

[0107] Reaction time / h 3PN / wt% ADN / wt% MGN / wt% Clear liquid Ni / ppm Conversion rate / % ADN selectivity / % 2 65.2 33.28 1.52 338 34.80 95.63 4 43.1 54.12 2.78 345 56.90 95.11 6 27.9 68.77 3.33 329 72.10 95.38 8 12.5 84.04 3.46 331 87.50 96.05 10 4.3 91.85 3.85 339 95.70 95.98

[0108] Table 12 shows that the raw material conversion rate of the two-step hydrocyanation reaction method comprising the nickel-bidentate phosphite ligand catalyst and the aromatic amine A12 of the present invention can reach 95.7%, the selectivity of ADN can reach more than 96%, and the content of the catalyst is stable during the overall reaction process, and the stability of the catalyst is good.

[0109] Example 7

[0110] A two-step hydrocyanation reaction method, in which pentenenitrile is used as a raw material to prepare adiponitrile in a reaction system containing aromatic amines under the action of a nickel-bidentate phosphite ligand catalyst, specifically:

[0111] (1) Material preparation: The catalyst used in this example is a nickel-bidentate phosphite ligand catalyst, wherein the bidentate phosphite ligand L26 has the same structural formula as that of the ligand L21, but the ligand L26 has a substituent structure shown in Table 13:

[0112] Table 13

[0113] Ligand L26 <![CDATA[R 1 ]]> <![CDATA[R 2 ]]> <![CDATA[R 3 ]]> <![CDATA[R 4 ]]> <![CDATA[Z 1 ]]> <![CDATA[Z 2 ]]> <![CDATA[Z 3 ]]> <![CDATA[Z 4 ]]> <![CDATA[Z 5 ]]> Substituents methyl Isopropyl Tert-butyl methyl methyl methyl hydrogen methyl Tert-butyl

[0114] The ligand L26 and nickel powder are combined to prepare a nickel-bidentate phosphite ligand catalyst.

[0115] (2) Two-step hydrocyanation reaction method: nickel-bidentate phosphite ligand catalyst (4.0 mmol), triphenylboron (8.0 mmol), aromatic amine A10 (2.0 mmol) and 3PN (2.0 mol) were placed in a stainless steel reactor. After replacing with nitrogen, the reaction system was heated to 60°C; then hydrocyanic acid (1.95 mol) was slowly added to the reactor using a pump, and the addition time lasted for 2 hours; after the addition was completed, the reaction was continued at 60°C; as the reaction proceeded, the reaction system was sampled and analyzed at different times. The results are shown in Table 14.

[0116] Table 14

[0117] Reaction time / h 3PN / wt% ADN / wt% MGN / wt% Clear liquid Ni / ppm Conversion rate / % ADN selectivity / % 2 65.7 33.18 1.12 345 34.3 96.73 4 44.1 53.89 2.01 347 55.9 96.40 6 28.1 69.18 2.72 328 71.9 96.22 8 12.7 83.92 3.38 335 87.3 96.13 10 4.5 91.75 3.75 337 95.5 96.07

[0118] It can be verified from Table 14 that the selectivity of ADN in the two-step hydrocyanation involving the nickel-bidentate phosphite ligand catalyst and aromatic amine A10 of the present invention can reach more than 96%, and the Ni content of the clear liquid does not decrease significantly during the reaction process, indicating that the catalytic performance of the catalyst is relatively stable during the reaction process.

[0119] Example 8

[0120] A two-step hydrocyanation reaction method, in which the catalyst, reaction raw materials and control parameters used are the same as those in Example 5, except that the aromatic amine added in this example is aromatic amine A2; as the reaction proceeds, the reaction system is sampled and analyzed at different times, and the results are shown in Table 15.

[0121] Table 15

[0122] Reaction time / h 3PN / wt% ADN / wt% MGN / wt% Clear liquid Ni / ppm Conversion rate / % ADN selectivity / % 2 70.3 28.53 1.17 340 29.70 96.06 4 52.3 45.79 1.91 322 47.70 96.00 6 36.57 61.03 2.4 298 63.43 96.22 8 21.52 75.34 3.14 285 78.48 96.00 10 12.11 84.56 3.33 264 87.89 96.21

[0123] Combining Table 10 and Table 15, it can be confirmed that compared with the two-step hydrocyanation reaction method using aromatic amine A2, the catalyst stability in the two-step hydrocyanation reaction method using aromatic amine A11 is higher and the reaction rate performance is also better. In the actual reaction process, different aromatic amines can be selected according to specific working conditions to catalyze the two-step hydrocyanation reaction method.

[0124] Comparative Example 1

[0125] A one-step hydrocyanation reaction method, in which the catalyst, reaction raw materials and control parameters used are the same as those in Example 1, except that no aromatic amine is added in this comparative example; as the reaction proceeds, the reaction system is sampled and analyzed at different times, and the results are shown in Table 16.

[0126] Table 16

[0127] Reaction time / h Butadiene / wt% 3PN / wt% 2M3BN / wt% Clear liquid Ni / ppm Conversion rate / % 3PN selectivity / % 1 45.52 49.57 4.91 353 54.48 90.99 2 37.21 56.65 6.14 310 62.79 90.22 3 29.21 63.76 7.03 260 70.79 90.07 4 19.54 71.99 8.47 223 80.46 89.47 5 13.23 78.23 8.54 175 86.77 90.16

[0128] Combining Table 3 and Table 16, it can be confirmed that the one-step hydrocyanation reaction method of the present invention contains an aromatic amine of a specific structure, so that the Ni content of the clear liquid of the catalyzed one-step hydrocyanation reaction method is relatively stable during the reaction process. Compared with Example 1, the Ni content of the clear liquid in Comparative Example 1 decreases faster (the Ni content of the clear liquid decreases to 50% of the initial amount after 5 hours of reaction), which verifies that the aromatic amine A2 in the hydrocyanation reaction method of the present invention has a better effect in stabilizing the catalyst; in addition, the one-step hydrocyanation reaction method in Comparative Example 1 has a slower reaction rate than that in Example 1, which verifies that the aromatic amine A2 in the hydrocyanation reaction method of the present invention has a better effect in increasing the reaction rate.

[0129] Comparative Example 2

[0130] A two-step hydrocyanation reaction method, in which the catalyst, reaction raw materials and control parameters used are the same as those in Example 5, except that no aromatic amine is added in this comparative example; as the reaction proceeds, the reaction system is sampled and analyzed at different times, and the results are shown in Table 17.

[0131] Table 17

[0132] Reaction time / h 3PN / wt% ADN / wt% MGN / wt% Clear liquid Ni / ppm Conversion rate / % ADN selectivity / % 2 75.6 23.44 0.96 340 24.40 96.07 4 61.3 37.22 1.48 302 38.70 96.18 6 46.7 51.2 2.1 264 53.30 96.06 8 30.21 67.01 2.78 225 69.79 96.02 10 20.11 76.75 3.14 187 79.89 96.07

[0133] Combining Table 10 and Table 17, it can be verified that the aromatic amine with a specific structure contained in the two-step hydrocyanation reaction method of the present invention plays a role in stabilizing the catalyst (nickel content) in the reaction system. The Ni content of the supernatant in Comparative Example 2 decreases rapidly (the Ni content of the supernatant is reduced to 55% of the original after 10 hours of reaction), while the Ni content of the supernatant in Example 5 remains 96% of the initial amount after 10 hours. In addition, the reaction rate of the two-step hydrocyanation in Example 5 is greater than the reaction rate in Comparative Example 4, which verifies that the aromatic amine A11 has a better effect in improving the reaction rate.

[0134] Comparative Example 3

[0135] A one-step hydrocyanation reaction method, in which pentenenitriles are prepared from butadiene as a raw material under the action of a nickel-monodentate phosphite ligand catalyst and an aromatic amine A2; wherein the result of the monodentate phosphite ligand L11 is as follows:

[0136]

[0137] The monodentate phosphite ligand L11 has a substituent structure as shown in Table 18:

[0138] Table 18

[0139] Ligand L11 <![CDATA[R 1 ]]> <![CDATA[R 2 ]]> <![CDATA[R 3 ]]> Substituents Isopropyl hydrogen methyl

[0140] The ligand L11 and nickel powder are combined to prepare a nickel-monodentate phosphite ligand catalyst.

[0141] The raw materials and control parameters of the one-step hydrocyanation reaction method in this comparative example are the same as those in Example 1. As the reaction proceeds, the reaction system is sampled and analyzed at different times. The results are shown in Table 19.

[0142] Table 19

[0143]

[0144]

[0145] Combining Table 3 with Table 19, it can be confirmed that the nickel-bidentate phosphite ligand catalyst used in the hydrocyanation reaction method of the present invention has a higher product selectivity in the process of catalyzing the one-step hydrocyanation reaction method than the nickel-monodentate phosphite ligand catalyst used in Comparative Example 3, reflecting that the bidentate phosphite ligand plays an important role in improving the selectivity of 3PN; in addition, the Ni content of the clear liquid does not change much during the reaction of Example 1 and Comparative Example 3, confirming the effect of aromatic amine A2 in stabilizing the catalyst performance.

[0146] Comparative Example 4

[0147] A two-step hydrocyanation reaction method is disclosed. In the reaction, pentenenitrile is prepared from butadiene as a raw material under the action of a nickel-monodentate phosphite ligand catalyst and an aromatic amine A11; wherein the nickel-monodentate phosphite ligand catalyst is prepared from a ligand L11 and nickel powder.

[0148] The raw materials and control parameters of the two-step hydrocyanation reaction method in this comparative example are the same as those in Example 5. As the reaction proceeds, the reaction system is sampled and analyzed at different times. The results are shown in Table 20.

[0149] Table 20

[0150] Reaction time / h 3PN / wt% ADN / wt% MGN / wt% Clear liquid Ni / ppm Conversion rate / % ADN selectivity / % 2 80.9 15.7 3.4 340 19.10 82.20 4 62.9 30.55 6.55 335 37.10 82.35 6 46.72 43.75 9.53 332 53.28 82.11 8 29.52 57.78 12.7 329 70.48 81.98 10 19.95 65.56 14.49 326 80.05 81.90

[0151] Combining Table 10 and Table 20, it can be verified that the hydrocyanation reaction method of the present invention uses a nickel-bidentate phosphite ligand catalyst, and the product selectivity in the process of catalyzing the two-step hydrocyanation reaction method is higher than that of the nickel-monodentate phosphite ligand catalyst used in Comparative Example 4, reflecting that the bidentate phosphite ligand plays an important role in improving the selectivity of 3PN; in addition, the Ni content of the clear liquid does not change much during the reaction of Example 5 and Comparative Example 4, which verifies that the aromatic amine A11 plays an effect of stabilizing the catalyst performance during the two-step hydrocyanation process.

[0152] Comparative Example 5

[0153] A two-step hydrocyanation reaction method, the catalyst, reaction raw materials and control parameters used in the reaction are the same as those in Example 5, except that A11-1 containing one aromatic ring and A11-2 containing three aromatic rings are used instead of A11 in this comparative example. As the reaction proceeds, the reaction system is sampled and analyzed at different times, and the results are shown in Table 21.

[0154]

[0155] Table 21

[0156]

[0157] Combining Table 10 and Table 21, it can be verified that the aromatic amine with a specific structure contained in the hydrocyanation reaction method of the present invention plays a role in stabilizing the catalyst (nickel content) in the reaction system, which is specifically manifested as follows: the Ni content of the supernatant in Comparative Example 5 decreases rapidly (the Ni content of the supernatant is reduced to 75% and 72% of the original after 10 hours of reaction), while the Ni content of the supernatant after 10 hours in Example 5 still maintains 96% of the initial amount; this shows that the aromatic amine with a specific structure contained in the hydrocyanation reaction method of the present invention is more conducive to stabilizing the catalyst and reducing catalyst loss; in addition, the reaction rate of the two-step hydrocyanation in Example 5 is greater than the reaction rate in Comparative Example 5, which verifies that the aromatic amine A11 is superior to A11-1 containing one aromatic ring and A11-2 containing three aromatic rings in improving the reaction rate.

[0158] It should be noted that the above contents are further detailed descriptions of the present invention in combination with specific implementation methods, and it cannot be determined that the specific implementation of the present invention is limited to these descriptions; the dimensional data of this embodiment does not limit the technical solution, but only shows one of the specific working conditions. For ordinary technicians in the technical field to which the present invention belongs, several simple improvements and modifications can be made without departing from the concept of the present invention, which should be regarded as falling within the scope of protection of the present invention.

Claims

1. A hydrocyanation reaction method, characterized in that: The hydrocyanation reaction method is carried out in a reaction system containing an aromatic amine under the action of a nickel-bidentate phosphite ligand catalyst, wherein the structure of the aromatic amine is: Among them, X 1 -X 3 Group and Y 1 -Y 3 The groups include any one of hydrogen, alkyl, alkoxy, alkylamino, hydroxyl, and amino.

2. The hydrocyanation reaction method according to claim 1, characterized in that: The structural formula of the alkyl group is -R, and the structural formula of the alkoxy group is The structural formula of the alkylamino group is Wherein, the R group includes any one of methyl, ethyl, isopropyl and tert-butyl.

3. The hydrocyanation reaction method according to claim 1, characterized in that: The structure of the bidentate phosphite ligand is: Among them, R 1 -R 4 and Z 1 -Z 5 The groups include any one of hydrogen, methyl, ethyl, isopropyl, tert-butyl, and methoxy.

4. The hydrocyanation reaction method according to claim 1, characterized in that: The mass ratio of the nickel-bidentate phosphite ligand catalyst to the aromatic amine is 1:(0.05-0.8), preferably 1:(0.1-0.6).

5. The hydrocyanation reaction method according to any one of claims 1 to 4, characterized in that: The hydrocyanation reaction method is a hydrocyanation reaction method for preparing adiponitrile.

6. The hydrocyanation reaction method according to claim 5, characterized in that: The hydrocyanation reaction method includes a one-step hydrocyanation reaction method for preparing pentenenitrile using butadiene as a raw material; Preferably, the reaction temperature of the one-step hydrocyanation process is 40-110°C, preferably 50-95°C.

7. The use according to claim 6, characterized in that: In the one-step hydrocyanation reaction method, X in the structure of the aromatic amine 1 , X 3 , Y 1 , Y 3 The groups are selected from hydrogen or alkyl, X 2 , Y 2 The groups are selected from alkyl or alkoxy groups; And / or, in the one-step hydrocyanation reaction method, the mass ratio of the nickel-bidentate phosphite ligand catalyst to butadiene is (0.5-3):1000, preferably (0.75-2.5):1000.

8. The use according to claim 5, characterized in that: The hydrocyanation reaction method also includes a two-step hydrocyanation reaction method for preparing adiponitrile using pentenenitrile as a raw material; Preferably, the reaction temperature of the two-step hydrocyanation method is 35-90°C, preferably 40-80°C.

9. The use according to claim 8, characterized in that: In the two-step hydrocyanation reaction method, X in the structure of the aromatic amine 1 , X 3 , Y 1 , Y 3 The groups are selected from any one of hydrogen, alkyl or alkoxy, X 2 , Y 2 The group is selected from alkoxy or alkylamino; And / or, in the two-step hydrocyanation reaction method, the mass ratio of the nickel-bidentate phosphite ligand catalyst to pentenenitrile is (0.5-3):1000, preferably (0.75-2.5):1000.

10. The use according to claim 8, characterized in that: The two-step hydrocyanation reaction method is carried out in the presence of a co-catalyst, wherein the co-catalyst includes one of zinc chloride, aluminum chloride, ferric chloride, titanium tetrachloride, and triphenylboron; preferably, the mass ratio of the nickel-bidentate phosphite ligand catalyst to the co-catalyst is (0.2-0.8):1, preferably (0.3-0.7):1.

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